1. Field of the Invention
The invention relates to the functionalization of balls, particularly deformable balls, especially in the field of sports and/or of physical rehabilitation and/or of leisure. The invention particularly applies to tennis balls.
2. Description of Related Art
In ball sports and physical restoration based on such objects, it is useful to have statistics enabling players to analyze their game and medical staff to assess the quality of the exercises practiced by the patients. Usually, such statistics are manually collected by, for example, counting the number of shots, bounces, or others applied by a player or a patient on a ball for a determined time period.
It is also advantageous to integrate in balls electronic functions enabling to automatically make statistics and/or to convert and store the mechanical energy provided to these objects during the use thereof into electric energy.
Document US 2011/136603 discloses a sports ball comprising a deformable shell defining an inner space under pressure, such as for example a tennis ball, and comprising a piezoelectric element arranged on or inside of the deformable shell to convert the mechanical energy corresponding to the shell deformation into electric energy, and an electronic circuit comprising a battery for storing the electric energy thus generated and a processing circuit powered with the battery, such as for example an accelerometer, a pressure sensor, or a GPS.
This document is however mute as to the way of integrating these different components in the ball. Now, this integration generally aims at a plurality of objects, which may be contradictory.
First, a high rate of conversion of mechanical energy into electric energy is desired, since the electric energy may be used to power electronic circuits requiring a high energy level to operate.
Then, the components integrated in the ball should provide a minimum hindrance to the aerodynamic properties and the deformations thereof, since a functionalized ball having mechanical characteristics close and ideally identical to those of a conventional ball in order to be used instead of it is desired, particularly in sports, where balls must satisfy very strict criteria to be deemed compliant.
Finally, it is preferable for the components to be mechanically robust to face mechanical stress which may be high due to the shocks and significant accelerations undergone by the ball. The inventors have further noted, in the context of trials on different types of electronic circuit and of electronic connections integrated in a tennis ball, frequent breakages of these components.